The last successful astronomical instrument observation campaign aboard SOFIA. Press release from the Max Planck Institute for Radio Astronomy, Bonn.
Source: Max Planck Institute for Radio Astronomy.
May 4, 2022 – With the joint decision by NASA and the German Aerospace Center (DLR) to cease flight operations of the Stratospheric Observatory for Infrared Astronomy (SOFIA) in September 2022, unique scientific opportunities for high-resolution images also become available at the end of far-infrared spectroscopy using the SOFIA. German Spectrometer GREAT, the German receiver for astronomy at terahertz frequencies. GREAT is a development of the Max Planck Institute for Radio Astronomy and the Cologne Submillimeter Astronomy Observatory (KOSMA)/University of Cologne, in collaboration with the DLR Institute for Optical Sensing Systems, and was largely independent of the German Space Agency’s (DLR) budget funder. Feedback with GREAT has also been in high demand from the general SOFIA user community.
The Stratospheric Observatory for Infrared Astronomy (SOFIA) with the German GREAT spectrometer on board will depart from New Zealand in July and August 2022 on the last 20 observation flights. With the joint decision by NASA and the German Aerospace Center (DLR) to halt flight operations in September 2022, the unique scientific opportunities for high-resolution far-infrared spectroscopy made possible by GREAT have also ended.
Using SOFIA, a converted Boeing aircraft with a flight altitude of more than 13 kilometers, researchers can monitor a wavelength range of light inaccessible from Earth. The GREAT (German Terahertz Astronomy Receiver) aboard SOFIA can create a kind of chemical fingerprint of large areas of the sky with high spatial and spectral resolution. GREAT is a development of the Max Planck Institute for Radio Astronomy and the Cologne Submillimeter Astronomy Observatory (KOSMA) / University of Cologne, in collaboration with the DLR Institute for Optical Sensing Systems. The development was funded by the respective institutes, the German Aerospace Center (DLR) and within the framework of the 956 Collaborative Research Center with funding from the German Research Foundation (DFG).
Since the first light aboard SOFIA on April 1, 2011, GREAT has conducted nearly 250 successful science flights, collecting 2,000 hours of unique scientific data of great value to future generations that would not otherwise have been observed. The spectrometer’s operating frequencies were specifically chosen to capture spectral lines of high astrophysics relevance in the far-infrared region, where the Earth’s atmosphere is quite opaque to ground-based observations.
GREAT – in close collaboration with interested international scientists – has covered a wide range of scientific topics, from exploration of Earth’s atmosphere and planets to exploration of star formation, physics and chemistry of the interstellar medium in the Milky Way and nearby galaxies. A particular focus has been on efficient large-scale mapping of the atomic microstructure lines of carbon and oxygen, which are the strongest cooling lines of the star-forming interstellar medium.
Among the new molecules discovered with GREAT, the discovery of the universe’s first molecular bond, the helium hydride molecule, HeH+, has received the most international attention. The scientific results of GREAT observations have been presented in numerous publications in scientific journals, including the results of the first research trips in a special volume of Astronomy and Astrophysics, and in several papers at relevant conferences.
Immediate access to the airborne platform, in contrast to space missions, has enabled the GREAT consortium to continuously develop the device with the latest technology. Starting with single-channel detectors with liquid helium cooling, the instrument was upgraded in 2015-16 to become the most powerful FIR array heterodyne spectrophotometer ever, operating with 14 + 7 pixels simultaneously in two frequency bands. It exceeds previous space experiments in speed of observation by more than an order of magnitude. The publication describing the instrument was awarded the 2018 THz Science Paper Award by the prestigious IEEE Microwave Theory and Techniques Society.
The GREAT team and its user community are now looking forward to the successful completion of the ongoing Ninth Cycle Observation Projects during the upcoming Southern Hemisphere Final Observation Campaign.
GREAT, “German Receiver for Astronomy at Terahertz Frequencies”, is a development of the Max Planck Institute for Radio Astronomy and the Cologne Submillimeter Astronomy Observatory (KOSMA)/University of Cologne, in collaboration with the DLR Institute for Optical Sensing Systems. The development was funded by the institutes concerned, by the German Aerospace Center (DLR) as part of grants 50 OK 1102, 1103, and 1104 and as part of the 956 Collaborative Research Center funded by the German Research Foundation (DFG).